Results and discussion
Works Cited
- Our results showed that the antibiotics, nalidixic acid and tetracycline, did inhibit the growth of serratia marcescens. The zone of inhibition was nonexistent in penicillin but it was 6 mm in tetracycline and 25 mm in nalidixic acid. Because of this, the hypothesis was supported.
- It also showed the disinfectant hypothesis was rejected because the disinfectants did not work as well as the antibiotics and barely stopped anything from growing. My prediction was possibly supported because the germ x was most affective. For the white vinegar, it grew from 6 mm into 8 mm, for the germ x it grew from 6 mm to 9mm , the control was noneffective, the dish soap either barely worked( 6mm to 7 mm) or worked greatly ( 6mm to 45 mm)
- Serratia Marcescens was also found to be gram negative.
Disinfectants explanation
- Basillo, Anía J., MD, and Cunha A. Burke, MD. "Serratia: Background." Medscape. N.p., 21 Feb. 2013. Web
- "The Effect of Alcohol and Non-Alcohol Based Hand Sanitizers on the Growth of Serratia Marcescens and Escherichia Coli." - Free Online Library. N.p., 1 Jan. 2001. Web.
- "Nalidixic Acid." Netdoctor. N.p., 26 May 2011. Web.
- Paddock, Mike. "What Is Penicillin? How Do Penicillins Work?" MNT. N.p., 18 Feb. 2011. Web.
- "Tetracycline Tablets." Netdoctor. N.p., 17 June 2011. Web.
Even though many people do think that germ x and other antibacterial gels are the same, they actually aren't. Germ x contains alcohol which kill off most germs. Non alcohol sanitizers contain benzalkonium chloride which some bacteria actually do thrive in. While doing research I found that Serratia Marcescens and many other bacterias still survive in non alcohol sanitizers and do not in alcohol sanitizers. So alcohol control or delete some of the bacteria cells.
Antibiotics - Explanation
Although penicillin is a universal antibiotic, of sorts, when researching about it I learned it is most effective for diseases effecting the throat, such as strep throat. However, when researching about nalidixic acid I learned that it is an antibiotic most commonly used for urinary infections and tetracycline is most commonly used for pneumonia and various things such as urinary or respiratory infections. Knowing that serratia marcescens is a bacteria caused by these types of infections I could conclude that these would better stop the bacteria from growing on the agar plate.
Lab Study B: Antibiotics
- The three antibiotics I chose to use were penicillin, nalidixic acid, and tetracycline.
- Hypothesis: The antibiotics will inhibit the growth of the bacteria .
- Prediction: If the nalidixic acid and tetracycline inhibit the growth then these antibiotics fight against serratia marcescens, whereas if the penicillin does not inhibit the growth then it's ingredients have no effect on the bacteria.
- Method: Split the agar dish into four sections swabbing each section in a different direction with serratia. Then I added my antibiotics and control and taped it shut.
Lab Study A: Disinfectants
- The three disinfectants I chose were germ x, dish soap, and white vinegar
- methods: I covered an agar plate in the bacteria and split it into four. I then but a small amount of 3 disinfectant into each of the quarters and held one as a control. I then refrigerated it for 36-48 hours.
- Hypothesis: I hypothesize that the disinfectants will inhibit the growth or kill the bacteria.
- Prediction: If the germ x will stop the bacteria, then the use of alcohol as an antiseptic is more affective then most chemicals
What is serratia marcescens?
- It was discovered in 1819 by Bartolomeo Bizio, who was a pharmacist from Italy.
- Serratia marcescens is a rod shaped bacteria varying from reds to pinks that often leads to different respiratory or urinary infections and at most severe, can lead to pneumonia.
- It looks like blood clots found in starchy foods.
- When infected with a disease from the bacteria serratia marcescens, patients will experience symptoms such as fevers, chills, and respiratory distress.
- It is found in soil , water and plants and can be traveled
via consumption or skin contact
Serratia Marcescens: The affects of disinfectants and antibiotics
By Olivia and Natalie